Novel narrow-band imaging magnifying endoscopic classification for early gastric cancer

Narrow-band imaging magnifying endoscopy is widely used in Japan, but still there is no set of consistent guidelines for gastric lesions.

To introduce a new narrow-band imaging magnifying endoscopic classification and report the accuracy of diagnosis in comparison to underlying histopathology of gastric lesions.

Two hundred and fifty-seven consecutive patients with early gastric cancer lesions were enrolled into this study. Narrow-band imaging magnifying images were classified into four categories based on abnormal microvascular patterns and irregularities in the superficial glandular structure: fine-network pattern, corkscrew pattern, intra-lobular loop pattern-1 and intra-lobular loop pattern-2. The narrow-band imaging magnifying endoscopic classification was compared with the histopathological findings.

Amongst the differentiated-type adenocarcinoma lesions, fine-network pattern, intra-lobular loop pattern-1, intra-lobular loop pattern-2 and corkscrew pattern were observed in 15.7%, 59.6%, 24.2% and 0.5%, respectively. Differentiated-type adenocarcinomas mainly exhibited fine-network pattern or intra-lobular loop pattern. In undifferentiated-type adenocarcinoma lesions, intra-lobular loop pattern-2 and corkscrew pattern were observed in 41.2% and 58.8%, respectively. Therefore, undifferentiated-type adenocarcinomas were all classified as intra-lobular loop pattern-2 and corkscrew pattern. The histopathological types were not equivalent with the narrow-band imaging magnifying classification categories (P<0.001).

The new narrow-band imaging magnifying classification that incorporates the intra-lobular loop pattern may be able to predict the histological subtype of most gastric carcinomas.